Download Learning through high-fidelity anaesthetic

Volume 107, Number 4, October 2011
British Journal of Anaesthesia 107 (4): 483–7 (2011)
doi:10.1093/bja/aer256
EDITORIAL I
Learning through high-fidelity anaesthetic simulation: the
role of episodic memory
T. W. Reader
Institute of Social Psychology, London School of Economics, Houghton Street, London WC2A 2AE, UK
E-mail: [email protected]
In this issue of the British Journal of Anaesthesia, Boet and
colleagues1 investigate skill retention after high-fidelity
simulator training for percutaneous cricothyroidotomy
insertion. This is an infrequently performed procedure particularly susceptible to error. The recent NAP4 study found
a 75% failure rate (six out of eight) in performance of
the procedure in UK intensive care units and emergency
departments.2 Failures were related to a lack of training
and technical difficulties. A key recommendation to
improve performance was using high-fidelity simulation to
teach trainees to recognize the key physical patient landmarks associated with cricothyroidotomy insertion. The
findings by Boet and colleagues lend weight to this solution. They found that anaesthetists retained cricothyroidotomy crisis management skills for up to 1 yr after
participating in a single cannot intubate, cannot ventilate
(CICV) scenario. In a post-training event (either 6 months
or a year after initial training), attending anaesthetists
recognized scenarios where percutaneous cricothyroidotomy insertion was required and applied the relevant knowledge and procedural skills for managing the situation. A
number of explanations are provided to account for this
retention of skills. These include the high-fidelity nature
of the training scenarios, the involvement of fully trained
anaesthetists, and the memorability of training episodes.
Developing this last point, Boet and colleagues invoke episodic memory theory to understand skill retention. Episodic
memory theory was proposed by Tulving,3 and it refers to
the ability of humans to remember and consciously
re-experience past events from their lives either at will or
on prompting.
As indicated above, high-fidelity simulator training provides anaesthetists with the opportunity to develop their
technical and non-technical skills for managing rare and
dangerous scenarios. It provides a safe multidisciplinary
learning environment, and depending on training objectives,
simulators can replicate a specific aspect of a clinical task or
an entire working environment.4 However, for simulator
training to be successful, anaesthetists must behave similarly
in real and simulated environments, and it is essential that
training scenarios and the tools used to measure performance are reliable and valid.5 Furthermore, if high-fidelity
simulation is to replace elements of class-based teaching
in anaesthesia, it is also necessary to consider how it
might enhance learning and practice.6 The cognitive psychology literature has much to offer in this respect, and as indicated by Boet and colleagues,1 episodic memory is especially
relevant. Through identifying the psychological mechanisms
and aspects of simulation that support learning and practice
in anaesthesia, we can optimize the design of high-fidelity
simulator training.
Episodic memory and high-fidelity
simulation
The episodic memory system represents a holistic approach
to understanding human memory, and it relates to the
encoding, storage, and retrieval of information learnt
during personally experienced situations and events.7 Episodic memories are centred on the self, with information on
context (e.g. the situation) and content (i.e. what was done
or learned) of an experience being linked together. Recalling
& The Author [2011]. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved.
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an ‘episode’ can involve bringing to mind a vast range of
information associated with an event, for example, visual
characteristics, smell and taste, emotional and physical sensations, behaviours undertaken, and knowledge learnt.
Experimental psychology and neuropsychological research
shows episodic memories to be created through the medial
temporal lobe ‘binding together’ the various neurological
traces of an episode.7 8 The left pre-frontal cortex is important for encoding and storage, and the right pre-frontal
cortex for retrieval. An event need only be experienced
once for information associated with it to be encoded,
stored, and made retrievable, with the detail and length of
retention depending on factors such as event significance,
uniqueness, and memory rehearsal. Depending on memory
encoding and storage (e.g. prominence in one’s mind, associations between elements of a memory), memories can be
retrieved at will through a mental search and retrieve strategy, or by a prompt that automatically activates memory
recall.
Due to the experiential nature of high-fidelity simulator
training, episodic memory appears relevant for understanding learning. Typically during simulation, anaesthetists
perform sensemaking activities to understand a time-limited
and realistic event. They employ technical and non-technical
skills to manage scenarios and cooperate with team
members, and the knowledge and skills learnt through training is contextually bound to a specific situation (e.g. CICV
scenarios). Similarly, episodic theory posits that episodic
memories bind together the context (e.g. scenario) and
content (e.g. knowledge learnt) associated with an event.
Memory retrieval is enhanced when the cues of the recall
environment are similar to those in the learning environment.9 A key advantage of simulator training is that it
helps anaesthetists to develop knowledge and skills for
rarely seen scenarios. However, if behavioural strategies
have not been learned to the point whereby they are ‘automatically’ used to manage an event, the actual deployment
of skills and knowledge learnt during simulation surely
depends on anaesthetists (i) recognizing cues within a reallife event that are analogous to a simulated episode, and
(ii) consciously recollecting the knowledge and behavioural
strategies used previously to manage that event. As episodic
memory theory describes factors that influence the encoding
and retrieval of such experiences, it may provide a useful framework to consider how the design of training scenarios can
support learning.
Using episodic memory to understand
learning from high-fidelity anaesthetic
simulation
Simulation research in anaesthesia focuses upon the validity,
reliability, feasibility, and learning effects from high-fidelity
simulator training.5 Theoretical analyses have established
standards for the expected properties of simulated training
scenarios (e.g. fidelity, physiological modelling).10 However,
there is also a need to understand the factors that make a
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Editorial I
simulated training scenario an effective teaching instrument
for influencing anaesthetic practice. Thus, it is worth discussing briefly the pedagogic advantages of simulator training,
and then considering how episodic memory theory might
advance our understanding of learning through anaesthetic
simulation.
The learning objectives of simulator-based training in
anaesthesia vary according to a variety of factors (e.g. expertise, knowledge, skill development). Consistent with the episodic memory perspective, simulator training teaches
participants to recognize scenarios (e.g. CICV), and to apply
the requisite memorized technical and non-technical skills
for managing the scenario.6 Factors such as existing knowledge, experience, and opportunities for practice in real life
and simulation will influence the extent to which skills and
knowledge become integrated into practice. The pedagogic
literature supports the underlying assumption that
simulator-based training will aid learning. For example, the
extent to which a training task is physical (e.g. manual application of a skill) and natural (e.g. realistic) improves skill
retention and future application, as does the similarity of
learning and practice environment.11 In addition, constructivist theories argue that learning is successful when the gap
between actual and intended knowledge of trainees is
identified, and training is structured so that participants
can sensemake and problem solve to reduce this gap.12
This perspective is consistent with simulation, with participants being afforded a safe learning space where they can
apply their skills and knowledge to solve challenging problems designed by experts.
Thus, from a pedagogic perspective, there is good evidence to assume that simulator training will facilitate learning. However, as discussed in the section above, learning and
practice after simulation may be dependent on the construction of scenarios and participant ability to recall training episodes. This is particularly the case for rare or unexpected
events, as there are fewer opportunities for the skills and
knowledge used to manage those events to become well
practiced, and to enter into routine behaviour. The episodic
perspective would appear to indicate at least two factors
as important for ensuring learning and future application.
The first factor is the memorability of training scenarios. It
would appear logical that details associated with a simulated
event (e.g. patient illness, environment, cues that prompted
decision-making, behavioural strategies) will be encoded
and recalled in higher levels of detail if simulated training
events are noteworthy in some dimension (e.g. novel, enjoyable, challenging, successful). A second factor is the extent
to which cues used in high-fidelity simulator scenarios to
influence decision-making are analogous to real life. Episodic
memory theory appears to indicate that the fidelity of scenarios will be important for future recall, particularly with rare
or unusual events. Specifically, the extent to which there is
similarity between simulated and real-life cues will increase
the likelihood that decision-making strategies learnt during
simulation are recalled in practice. This is consistent with
the expert decision-making literature, with decision-making
Editorial I
being influenced by the recall of strategies used to manage a
previous similar event.13
It is notable that the existing literature on high-fidelity
anaesthetic simulator training also provides insight and
speculation into how episodic memory systems might
support learning, retention, and recall. For example, investigation of critical event training (e.g. use of an Advanced
Cardiac Life Support protocol) has shown that the detailed
debriefing of participants after a training scenario results in
improved performance on a re-test scenario 6–9 months
later.14 From an episodic perspective, debriefings provide
trainees with an opportunity to reflect upon their practice
and consolidate memories. By watching one’s performance,
and noting the key situational cues and resultant
problem-solving and behavioural strategies, learning may
be reinforced through providing participants an opportunity
to retrieve and mentally rehearse key aspects of the training
episode.
The design of simulator scenarios also appears important
for learning and future recall of knowledge and skills associated with an episode. A study investigating oesophageal
intubation found that participant anaesthetist performance
did not improve when participating in a second simulated
training scenario.15 The study cites various reasons for this,
with it being indicated that anaesthetists may have
focused on other aspects of the simulation episode (e.g. haemorrhagic shock), rather than the technical learning goals
(e.g. solutions for managing oesophageal intubation). Episodic memory theory does not specify limitations on the
volume and detail of information that can be encoded and
stored within a single episode. However, it would appear
logical that anaesthetists who participate in highly stimulating scenarios attention may become overly focused on the
context of a scenario rather than the solutions, which may
not appear apparent or remarkable in comparison. As Boet
and colleagues1 indicate, this effect may be more pronounced for trainees rather than experienced specialists,
and supports the need to design scenarios which are memorable and have clear solutions, but are not overwhelming
in terms of information or pressure.
Simulator research has also provided some support for the
proposal that associating knowledge and skills with specific
anaesthetic scenarios will increase the likelihood of them
being used in practice. For example, in a study of standard
operating procedures used to prevent aspiration during rapid
sequence inductions, trainee knowledge was assessed
through questionnaires or simulated scenarios.16 The simulation group tended to use highly routinized rapid procedures
more frequently than the questionnaire group. In contrast,
they did not utilize the procedures cited as important by the
questionnaire group to the same extent. This is consistent
with episodic memory theory, as if knowledge of anaesthetic
procedures are not contextually ‘bound’ to a scenario (i.e.
they are learnt in a classroom setting), it may be less likely to
be applied during practice or simulation.
Recent research17 lends some weight to this point.
In comparison with a control group, anaesthetists who
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participated in simulator training for weaning patients from
cardiopulmonary bypass (CPB) demonstrated improved technical and non-technical skill in post-test assessments of real
practice. Simulator training was incremental, and participants performed in four high-fidelity CPB scenarios (each
with slightly different challenges) and then were debriefed.
After 2 and 5 weeks, anaesthetists weaned real CPB patients,
and those who participated in the simulator training demonstrated better performance than those attending interactive
seminars. Although such events are not rare, the findings
resonate with episodic memory theory, with memories for
knowledge and skills being associated with an event in highfidelity simulation and then utilized in real practice. Furthermore, through using a series of scenarios to explore different
aspects of task performance, it is consistent with pedagogic
theory on the benefits of structuring problem solving tasks to
incrementally aid learning. From this perspective, simulator
training can be used to carefully identify trainee knowledge
gaps and the simulated problem-solving tasks that will
support learning. For example, anaesthetic scenarios of
varying complexity have been used to distinguish between
early- and later-stage trained anaesthetists.18
Finally, although anaesthetic high-fidelity simulator training has been shown to improve technical and non-technical
skills, the extent to which training will continually develop
the skills of anaesthetists may depend on the continual
development of scenarios. For example, anaesthetists who
attend a high-fidelity anaesthetic crisis management scenario just once demonstrate improvements in their nontechnical skills, but further training sessions do not continue
to develop improvements in their skills.19 Episodic memory
systems are sometimes considered to be ‘one-shot’ in
nature, where the content and context of an experience
are bound to a specific event or moment. Repeating a training event or a near equivalent may consolidate or reinforce
the existing performance strategies that have been associated with a specific situation by helping behavioural strategies to be more instinctively applied. However, as
described above, to further facilitate knowledge and skill
development, trainees will need to experience new events
which allow them to sensemake and solve memorable and
distinct problems.
As high-fidelity simulation becomes more widely used in
anaesthetic training, it is increasingly important that we
understand how simulation is expected to influence learning
and practice (Table 1). In particular, episodic memory theory
may provide a useful framework to understand the pedagogic value of high-fidelity simulator training for rare training
events. At present, this proposal is speculative, yet it is not
inconsistent with decision-making and pedagogic theory.
However, it must be noted that several critiques have been
made of the episodic memory perspective.
Within the discipline of psychology, episodic memory
systems have been criticized due to their reliance on networks of cortical and subcortical brain regions.7 This makes
it difficult for psychologists to differentiate between memories using classical forms of memory categorization.20
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Editorial I
Table 1 Six factors that may influence learning and practice after high-fidelity simulator in anaesthesia
Steps
Description
Scenario memorability
Simulator training scenarios that are distinct or noteworthy in some dimension (e.g. novel, enjoyable)
may enhance the memorability of the cues connected with that scenario and the relevant behavioural
strategies. This appears particularly important for the simulation of rare anaesthetic events
Similarities between simulation and
practice
To support anaesthetists recalling the decision-making strategies used to manage an event in
simulation, the cues designed to influence decision-making in a simulator scenario should demonstrate
high-fidelity in order to prompt recognition and recall in practice
Debriefing participants
Video-supported debriefing after simulator training will provide anaesthetists with the opportunity to (i)
note the key situational cues and associated problem-solving strategies associated with a particular
anaesthetic scenario, and (ii) unconsciously consolidate and rehearse their memories for key elements
of the training episode
Avoiding overly complex training
scenarios
For training scenarios that are overly stimulating or complex, learning for routine aspects of scenario
management may be sub-optimal due to participant’s being overly focused on situational context (e.g.
managing stress) and not problem-solving. This is particularly the case for trainee anaesthetists, who
may become overwhelmed by the pressure of a training episode
Incrementally introducing new
problem-solving tasks
For training intricate problem-solving or technical skills, dividing scenarios into smaller elements may aid
learning. Specifically, incremental problem-solving will allow participants to identify and learn solutions
for the different problems that may be faced during a complex anaesthetic scenario. This will be
especially beneficial for trainees. However, for crisis management training, training events should unfold
as they would in reality (i.e. managing a crisis until its conclusion)
Refreshing the content of training
scenarios
To continually enhance the technical or non-technical skills of anaesthetists, new and challenging
training scenarios will need to be developed. Participants who attend repeated anaesthetic simulated
training events may reinforce, but not further develop, the skills learnt during the initial stages of training
Also, episodic memory theory is a relatively new and developing field, and new discoveries are emerging. For example,
there are similarities between the neural processes used to
recall an episode, and those used to imagine a future
event.21 Age22 and sleep23 influence the formation of new
episodic memories, and a variety of factors can result in
memories being incorrectly encoded or retrieved.24 Finally,
it must be noted that numerous other memory systems influence learning. For example, the retrieval of information is
influenced by presentational order of data.25 Such findings
do not run counter to episodic memory theory, but rather
they highlight the extent to which the design of simulator
training can benefit from adopting principles from cognitive
science. As the use of high-fidelity simulation increases in
anaesthetic training, so must our understanding of how we
expect simulation to influence the learning and practice of
anaesthetists.
Conflicts of interest
None declared.
References
1 Boet S, Borges BCR, Naik VN, et al. Complex procedural skills are
retained for a minimum of 1 yr after a single high-fidelity simulation training session. Br J Anaesth 2011; 107: 533– 9
2 Cook T, Woodall N, Harper J, Benger J, on behalf of the Fourth
National Audit Project. Major complications of airway management in the UK: results of the Fourth National Audit Project of
the Royal College of Anaesthetists and the Difficult Airway
Society. Part 2: intensive care and emergency departments. Br J
Anaesth 2011; 106: 632–42
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3 Tulving E. Precis of elements of episodic memory. Behav Brain Sci
1984; 7: 223– 68
4 Maran N, Glavin R. Low- to high-fidelity simulation: a continuum
of medical education? Med Educ 2003; 37: 22– 8
5 Boulet J, Murray D. Simulation-based assessment in anesthesiology: requirements for practical implementation. Anesthesiology
2010; 112: 1041–52
6 Murray D. Current trends in simulation training in anaesthesia: a
review. Minerva Anestesiol 2011; 77: 528–33
7 Tulving E. Episodic memory: from mind to brain. Annu Rev Psychol
2002; 53: 1– 25
8 Chadwick M, Hassabis D, Weiskopf N, Maguire E. Decoding individual episodic memory traces in the human hippocampus. Curr Biol
2010; 20: 544– 7
9 Godden D, Baddeley A. Context-dependent memory in two
natural environments: on land and underwater. Br J Psychol
1975; 66: 325– 31
10 Cumin D, Weller J, Henderson K, Merry A. Standards for simulation in anaesthesia: creating confidence in the tools. Br J
Anaesth 2010; 105: 45– 51
11 Arthur W, Bennett W, Stanush P, McNelly T. Factors that influence
skills decay and retention: a quantitative review and analysis.
Hum Perform 1998; 11: 57–101
12 Daniels H. Vygotsky and Pedagogy. London: Routledge, 2003.
13 Klein G, Zsambok C. The recognition-primed decision (RPD)
model: looking back, looking forward. In: Zsambok C, Klein G,
eds. Naturalistic Decision Making. Mahwah: LEA, 1997; 285– 92
14 Morgan P, Tarshis J, LeBlanc V, et al. Efficacy of high-fidelity
simulation debriefing on the performance of practicing
anaesthetists in simulated scenarios. Br J Anaesth 2009; 103:
531– 7
15 Olympio M, Whelan R, Ford R, Saunders I. Failure of simulation
training to change residents’ management of oesophageal intubation. Br J Anaesth 2003; 91: 312– 8
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16 Zausig Y, Bayer Y, Hacke N, et al. Simulation as an additional tool
for investigating the performance of standard operating procedures in anaesthesia. Br J Anaesth 2007; 99: 673–8
17 Bruppacher H, Alam S, LeBlanc V, et al. Simulation-based training
improves physicians’ performance in patient care in high-stakes clinical setting of cardiac surgery. Anesthesiology 2010; 112: 985–92
18 Murray D, Boulet J, Avidan M, et al. Performance of residents and
anesthesiologists in a simulation-based skill assessment.
Anesthesiology 2007; 107: 705–13
19 Yee B, Naik V, Joo H, et al. Non-technical skills in anesthesia crisis
management with repeated exposure to simulation-based education. Anesthesiology 2005; 103: 241–8
20 Toth J, Hunt R. Not one versus many, but zero versus any: structure and function in the context of the multiple memory-systems
21
22
23
24
25
debate. In: Foster J, Jelicic M, eds. Memory: System, Process, or
Function? Oxford: Oxford University Press, 1999: 232– 72
Schacter D, Addis D, Buckner R. Episodic simulation of future
events: concepts, data, and applications. Ann N Y Acad Sci
2008; 1124: 39– 60
Maguire E, Frith C. Aging affects the engagement of the hippocampus during autobiographical memory retrieval. Brain 2003;
126: 1511– 23
Aly M, Moscovitch M. The effects of sleep on episodic memory in
older and younger adults. Memory 2010; 18: 327–34
Johnson M, Hashtroudi S, Lindsay D. Source monitoring. Psychol
Bull 1993; 114: 3 –28
Murdock B. The serial position effect of free recall. J Exp Psychol
1962; 64: 482– 8
British Journal of Anaesthesia 107 (4): 487–9 (2011)
doi:10.1093/bja/aer255
EDITORIAL II
Local infiltration analgesia for total knee arthroplasty
C. J. L. McCartney 1* and G. A. McLeod 2
1
2
Department of Anesthesia, Sunnybrook Health Sciences Centre, University of Toronto, 2075 Bayview Avenue, ON, Canada M4N 3M5
University Department of Anaesthesia, Ninewells Hospital and Medical School, Dundee, Tayside, UK
* E-mail: [email protected]
Total knee arthroplasty (TKA) is a common surgical procedure but is painful and requires careful management
in order to balance patient comfort and early postoperative function. Traditional methods of pain management
such as the use of parenteral opioids provide inadequate
pain relief and are limited by excessive adverse effects.
In contrast, epidural analgesia is used in many institutions
and can provide good pain control. However, the failure
rate with epidural analgesia approaches 20% and is commonly associated with adverse effects such as excessive
motor block.1 The more recent use of peripheral nerve
blocks such as continuous femoral block has been
shown to provide pain control equivalent to epidural techniques, but with fewer adverse effects, especially when
used as part of a multimodal analgesic regimen.2 Consequently, the use of continuous femoral block in this
context has come to be regarded by many to be the
gold standard for pain relief after TKA.3 However, placing
continuous perineural catheters is technically demanding,
requires additional anaesthetic time, and is an acquired
skill. Although a femoral block provides effective analgesia
for the anterior aspect of the knee joint, careful management is important to avoid significant motor block of the
quadriceps which can inhibit rehabilitation or more rarely
cause falls. An initial bolus of ropivacaine 2 mg ml21 and
subsequent infusion4 5 of ropivacaine 1 – 2 mg ml21
injected around the femoral nerve provides not only very
good postoperative pain relief, but also ready mobilization
on the evening of and days after surgery. A simpler technique that is available to more patients and that could be
provided by anaesthetists without subspeciality expertise
in regional anaesthesia would be desirable but only if it
guaranteed adequate and prolonged analgesia in the
postoperative period,
without
the
limitation
of
side-effects.
Local infiltration analgesia (LIA) at the surgical site has
become relatively common for a number of surgical procedures and can produce effective analgesia and has the
advantage of relative simplicity compared with other
regional anaesthesia techniques. The benefit of infiltration
of the knee after TKA was demonstrated in a small, though
well designed, randomized trial comparing local infiltration
against placebo.6 Subsequently, an effective protocol for
LIA was developed and then shown to provide effective
pain control and ability to ambulate in a series of 86 patients
having TKA.7 Since then, there have been 20 further studies
with several demonstrating improved pain control and
reduced adverse effects with the LIA technique compared
with placebo. Currently, only four studies have compared
LIA with other regional anaesthesia techniques; two studies
with epidural analgesia and two with continuous femoral
nerve block (FNB).
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